The kingdom has called the allegations "baseless", but has offered no evidence the writer ever left the consulate.
"At this time I implore President Trump and First Lady Melania Trump to shed light on Jamal's disappearance", wrote Cengzi.
Trump made Saudi Arabia the first stop on his first foreign trip as president in May 2017, but in recent weeks has appeared to sour a bit on Riyadh, complaining directly to King Salman about the cost of American support for the Saudi military and for OPEC oil price increases.
White House National Security Advisor, Ambassador John Bolton and White House Senior Advisor, Jared Kushner spoke to Saudi Arabian Crown Prince Mohammed Bin Salman yesterday about the missing Washington Post journalist.
He says he's spoken with the Saudis about what he called a "bad situation", but he did not disclose details of his conversations. Meanwhile, a newspaper close to Erdogan published the names and photographs of 15 Saudi men whom it said were sent to Istanbul to kill Khashoggi.
Turkish spokesman Hami Aksoy said authorities are "open to cooperation" and willing to examine the consulate grounds, though it was not clear when a search would take place.
Human rights activists and friends of Saudi journalist Jamal Khashoggi hold his pictures during a protest outside the Saudi Consulate in Istanbul, Turkey on October 8, 2018.
Reportedly, Turkish authorities say a team of Saudis killed Khashoggi, and USA intelligence intercepts show Saudi officials discussing an operation to lure Khashoggi - a Saudi citizen who had been living in the United States - back to Saudi Arabia from his home in Virginia and detain him.
Khashoggi had written a series of columns for the Washington Post that were critical of Saudi Arabia's assertive Crown Prince Mohammed bin Salman, who has led a widely publicized drive to reform the Sunni monarchy but has also presided over the arrests of activists and businessmen.
Broadcast by Turkey's TRT World channel and apparently obtained from security cameras, the footage shows vehicles driving up to the consulate, including black vans thought to be central to inquiries.
The sale is a "tremendous order for our companies", and if the kingdom doesn't buy its weaponry from the United States, they will buy it from others, he said.
'We have to find out who did it, ' Trump said. Saudi officials haven't acknowledged that.
Corker said he spoke to the Saudi ambassador to the United States about the situation, and was told that closed-circuit TV from the consulate did not record what happened. "The consulate officials can not save themselves by simply saying, 'He has left, '" Erdogan said earlier in the week.
The Washington Post also reported on Tuesday that U.S. intelligence officials had intercepted communications of Saudi officials discussing a plan to kidnap Khashoggi. The Turkish newspaper Hurriyet also published the image.
With every day, leaks from the Turkish investigation are drip-fed to the media here - and hope that Jamal Khashoggi might still be alive fades further.
Turkish claims that a well-known Saudi writer and government critic was slain inside his country's diplomatic mission in Turkey have put the Trump administration in a delicate spot.